Piston cooling for internalcombustion engines



May 12, 1953 G. PIELSTICK 2,638,080

PISTON COOLING FOR INTERNAL-COMBUSTION ENGINES Filed Dec. 50, 1950Patented May 12, 1953 PISTON COOLING FOR INTERNAL- COMBUSTION ENGINESGustav Pielstick, Saint Germain-en-Laye, France Application December 30,1950, Serial No. 203,583 In France May 15, 1950 1 Claim.

This invention relates to pistons for internal combustion engines,especially high-powered diesel engines.

The current trend in diesel engine construction is towards increasingvalues of the mean effective pressure, especially in the case ofsupercharged 4- cycle engines provided with turbine compressors.Experiments show that such an increase is mainly limited by theoperating temperatures in the pistons. Thus, in cylinders having anaverage bore diameter, at high piston velocities and with an effectivemean pressure of 14 kg./sq.cm., the conventional, non-cooled piston madeof aluminium alloy was approximately at the limit of its practicalpossibilities of use. Any further increase beyond such values wouldrequire the use of forced cooling for the piston, and this could only beachieved heretofore at the cost of considerable alterations in thepiston construction.

It is an object of the present invention to provide an improved pistonconstruction which incorporates new and improved forced cooling meanstherein. Another object is to provide such a construction which does notentail any considerable modication in the design of the piston itself. Afurther object is to provide such cooling means which are readilyremovable and adapted to be removed from one, and mounted on another,piston of standard construction.

With the above and further objects in view, the invention essentiallyprovides a piston with a cooling chamber formed above the piston pintherein, and a generally bell-shaped thin-walled member or jacketremovably integrally secured in said piston and pivoted on thepiston-pin, having its closed upper end sealing said cooling chamber andextending down with its open lower end around the connecting rodsubstantially to the lower end of the skirt of the piston, duct means insaid jacket member leading to and from said cooling chamber, and inletand outlet connec tions at the lower end of said member projecting outof the piston skirt for the circulation of a cooling iiuid through saidmember and said cooling chamber.

The thin-walled jacket member is so constructed as not to hinder thefree expansion of the piston. The upper end of the member is seated inan aperture between the recess of the piston skirt and the coolingchamber, deiined by an inturned rib.

(CI. 12S-41.35)

According to the invention, a standard piston may be constructed for acomparatively wide range of engine power outputs.

An exemplary embodiment of the invention will now be described forpurposes of illustration and not of limitation, with reference to theaccompanying drawings, wherein:

Fig. l is an axial section of a piston constructed according to apreferred form of the invention;

IFig. 2 is a section on line II--II of Fig. 1; and

Fig. 3 is a section on the broken line III-III of Fig. 1.

As shown in the drawings, the piston I is mounted in the usual manner bymeans of a connecting rod 2 pivoted on the piston pin 3. A hollow jacketmember 4, having very thin Walls, is inserted in the piston I andsecured on the piston pin 3. The member 4 terminates at its top at thepiston cooling'chamber 5, and ducts t and l in the member 4 lead freelyinto and from the chamber 5. At its lower end the part 4 is providedwith hollow joints B, 9 which connect the internal space I0, II of thepart 4 with conduits I2 and I3 through which a cooling :Huid may be madeto flow.

In operation, when the motor requires a forced cooling for the piston,the cooling fluid is caused to circulate along the path indicated by thearrows f1, f2, f3, f4.

The same piston may also be used in connec tion with a motor operatingwithout the requirement of forced cooling.

Similarly, when the necessity arises of replacing a piston in the motor,the part 4 may be easily removed and mounted on the new piston.

It will be understood that modifications may be made in the details ofthe embodiment described and illustrated within the scope of theinvention.

What I claim is:

In a piston assembly for an internal combustion engine comprising apiston of a usual type, a connecting rod and a piston pin connecting thepiston and the connecting rod, an independent inner removablesubstantially bell-shaped thin walled jacket means with a solid upperportion removably located inside said piston and pivoted about saidpiston pin, said jacket means dening a completely closed cooling chamberin the upper part of said piston above said piston pin, duct means insaid jacket means leading into and out of said cooling chamber, anduid-intake and outlet connections at the lower end of said jacketmember, providing for a continuous and controlled flow of cooling fluidin said cooling chamber, the said jacket with its related uid ducts andconnections constituting a complete and single assembly adapted forinsertion in said piston.

GUSTAV PIELSTICK.

References Cited in the file of this patent UNITED STATES PATENTS l NameDate Burn Oct. 27, 1914 Number

